Narrow typed locale identifiers

[warflash]

Describe the feature

const { locale, locales } = useI18n()

Currently locale is typed as string and locales is string[].
The suggestion is to use tighter types like locale -> "en" | "de" in the case of a config like:

	i18n: {
		locales: [
			{ code: "en", iso: "en-US", file: "en.json" },
			{ code: "de", iso: "de-DE", file: "de.json" },
		],
	},

That would make type safe access to typed records possible. e.g.

const MIN_SEARCH_LEN_BY_LOCALE = {
	en: 3,
	de: 3,
	ko: 1,
}

const { locale, locales } = useI18n()

const minLen = MIN_SEARCH_LEN_BY_LOCALE[locale] 

Additional information

• Would you be willing to help implement this feature?
• Could this feature be implemented as a module?

Final checks

• Read the contribution guide (The contribution guideline of nuxt-modules/i18n is compliant with Nuxt too).
• Check existing discussions and issues.